Jumper for interconnecting spaced electric terminals



T. E. CURTIS Dec. 20, 1955 2 Sheets-Sheet l Filed June 14, 1952 INVENTOR 7770/1705 E. Cuff/'6 A GEA/7' Dec. 20, 1955 T. E. CURTIS 2,728,055

JUMPER FOR INTERCONNEJCTING Filed June 14, 1952 SPACED ELECTRIC TERMINALS 2 Sheets-Sheet 2 INVENTOR Th 00705 E. Cuff/s AGENT United States Patent 'O JUMPER YFOR INTERCONNECTIN G SPACED vELECTRIC TERMINALS Thomas E. Curtis, Hampton, Ga., assigner to Southern States .Equipment Corporation, a corporation of Georgia Application June 14, 1952, Serial No.

lClaim. :(Cl. 339-19) Another is to provide jumper means whereby an automatic a modified form of the lower end of switch stick used for In the lower end of the tube is hole 5. One end of ex- 2,728,055 Patented Dec. 20, 1955 lits loosely inside tube 3, a ring portion 1.2, a stop collar 13, and a lower open at the bottom. A flexible conducting shunt 15 electrically connects contact 2 spring 6 exerts a slight upward pull on contact 11, holding stop 13 against .the lower end Figure 3 shows a contact. This is simllar to contact of only one ring '12, ithas two spaced rings 17, .18. 'The lower part of contact 16 is the same as cylinder Figure l, and the same numerals are used the corresponding `parts of contact 16.

Such a stick may have .a length more. On top of the stick 19 is finger 21 extends laterally from the side spaced well below the rtop.

In the sid of cylinder 14, at the bottom, is .an angular slot 22 which is engageable with finger 21 by inserting 29 into cylinder i4 and then rotating stick 19, to forni a bayonet-type joint between stick 19 and jumper contact 11. form a unitary assembly with all parts alignment with one another.

Slight enlargements 22 at fthe end of slot v22 tend .to

prevent unintentional rotation of the Two insulators .23, 24 support, respectively, terminals 25, 26 which are normally connected together electrically by the fuse, switch arm, breaker 27. :Inserted between 24 and its respectiveterminal 28,29. These supports are .identical andfthey are shown in larger scale in Figures l0 and ll. Theyare reversible and .they are Ipositioned so 'that 'the 'hook on the .upper 25, 26 is a jumper support support points downwardly.

Supported by stick 19, the jumper is lifted up and Then is transmitted 12, and so the full force tact pressures between the contacts. The stick is thereby es- 26; and the Thus installed, as shown in Figure 6, the jumper is entirely out of the way and it can be left in service for a considerable time if necessary. The hook-and-ring holding means together with the strong pressures caused by spring 6 tend to preclude any Vaccidental misplacement ot the jumper. The switch stick is of such length as to enable a man standing on the ground to operate the equipment above him easily; and therefore it not removed the switch stick would be a serious hazard. Figure 7 in larger scale gives a side view of details of one insulator and its adjacent members. The insulator 23 has a metal cap 30 aixed to it and bolts 31, 31 are screwed into or otherwise engaged with cap 30 to hold terminal 25 securely to the insulator.

Figures and 1l show jumper support 28, which consists of a thin at plate 34 with free passage for bolts therethrough, and integral with the plate the contact making hook 28. The plate 34- may readily be inserted between insulator cap 30 and terminal 25, so that bolts 31-31 will then hold both support 28 and terminal 25 securely to insulator 23. Alternatively, two bolts 31, 31 may be used instead of four in securing terminal and support to the insulator. When the insulator is positioned as indicated in Figure 8, boltsiwill pass through holes 32- 32; when the insulator is positioned as in Figure 9, bolts will pass through holes 33-33.

Figure 2 shows a modified form of the spring-biased contact and their associated members. To the upper jumper contact 3S is fastened the outer tube 36 by means of screws 37, 37; and to the lower jumper contact 38 is fastened the inner tube 39 by means of screws 40,411. Slots 41, 41 are cut in opposite sides of tube 39, and screws 42, 42 are screwed into the walls of tube 36 with their inner ends projecting into slots 41, 41. Tube 39 makes a sliding tit inside of tube 36, and screws 42, 42 limit this sliding motion of tube 39.

The close-coil tension spring 43 is secured at its top end by being screwed over the helical groove in the lower end of contact 35. The lower end of spring 43 is similarly secured to the upper end of lower contact 38. Flexible conductor 44 is secured to both contacts 35 and 38, keeping them electrically connected regardless of their relative positions.

The long sleeve tit between tubes 36 and 39, holds contacts 35 and 38 always in good alignment, and screws 42, 42 prevent any relative twisting motion while allowing easy longitudinal motion between the two contacts. All parts are so proportioned that when in use the slots 41, 41 are covered by tube 36, and so the interior of the tubes is closed against the entrance of insects.

Normal positions of all parts are as indicated in Figure 2, and dimensions are such that when in use spring 43 is somewhat extended so that good contact pressures are imposed by the jumper contacts against the two jumper supports.

The spacing of bolts on such switch-type insulators generally conforms to previously determined standards, but insulators may be positioned so that the bolts may be located either according to Figure 8 or Figure 9. design of jumper support shown in Figure 10 makes the support ap the bolts 3 jumper supp ing on either ort as shown ma the right or the left si The plicable for use with either arrangement of 1, 31. Also the symmetrical design of the kes it suitable for mountde of the insulator and with the hook pointed either upwardly or downwardly. For larger insulators with diferently located bolts, diierent jumper support members may be provided.

jumper supports may be made as integral if desired such parts of electrical terminals such as 25 and 26.

each of the And For

various voltages, the spacing of insulators conforms to standards that are currently known and generally accepted, the higher voltage taking greater spacing between the' insulators.

And in order that the same jumper may be used on two or more voltagesA for which the insulator spacings are not too different, one contact of the jumper may have two or more rings as shown in Figure 3. would be used;

For the lower voltage, the rings 17 for the higher voltage, the ring 18 would make contact with the lower jumper support 29.

I claim:

A jumper for interconnecting a pair of spaced electric terminals comprising a rst contact engageable with one of the terminals and having a threaded portion, a second contact engageable with the other terminal and also having a threaded its end coils respectively in threaded engagement the threaded portions of said contacts, said spring being effective to establish a predetermined contact pressure between each contact and its associated terminal, a sleeve affixed to each contact, said sleeves being telescopically related to form an enclosure for said spring, a longituportion, a coil spring arranged with with dinal slot in one of said sleeves, and a pm secured in the other of said sleeves and disposed in said slot, engagement of said pin with the ends of said slot being respectively determinative of the minimum and maximum spacing between said contacts.

References Cited in the le of this patent UNITED STATES PATENTS 

